Frequency Modulation (FM) is a form of modulation in wireless communication which represents information as variations in the instantaneous center frequency of a carrier wave. Frequency modulation was chosen as a modulation standard for high frequency signal transmission. A plurality of FM frequencies (channels) each separated by a frequency spacing may be broadcasted by a transmitter tower, a radio station or by a transmitting FM radio device.
A FM radio receiver of a FM radio includes a tuner with a tunable local oscillator (LO) may scan or search for broadcasted local FM frequency channels. Scanning may be performed by tuning the LO across the full tuning range of the LO or sweep the LO back and forth over a narrower tuning range to search for a signal of interest such as a FM channel. A FM channel may be detected or tuned if the FM radio receiver may successfully process a signal of sufficient signal amplitude, and/or the tuner may be able to establish an intermediate frequency (IF) signal that may be substantially the same or close to a defined offset of the FM radio receiver. When signals of two similar frequencies (from different broadcast stations or a neighboring broadcasting device) are received by the FM radio receiver, the FM radio receiver may process the stronger of two signals being broadcasted on the same frequency.
Radio Data System (RDS) or Radio Broadcast Data System (RBDS) standard format may be transmitted as a sub-carrier on the FM signals. The RDS/RDBS data format may contain information such as alternate frequencies of the broadcast station, the clock time, program identification with known channel frequency, channel spacing, station ID, country code or country identity, regional links and Enhanced Other Networks (EON) etc.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.